Modern technology requires highly trained craft personnel to modify, maintain and operate complex technical electrical and electronic equipment. Changes and modifications are oftentimes made to the equipment requiring that craft personnel, such as repair personnel and operators, be retrained to modify and to maintain and operate the modified equipment. Training may be accomplished by sending the craft personnel to training courses taught by highly trained professional instructors or by requiring the craft personnel to take correspondence courses.
A problem arises in that requiring the craft personnel to attend training courses means that craft personnel are required to take time from their normal work functions to attend a formal training course. Another problem arises in correspondence courses in that craft personnel do not have the advantage provided by formal training courses of having an instructor clarify textbook material.